Machaeranthera tanacetifolia
Tanseyleaf tansyaster
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Family: Asteraceae · Type: Herb · Native
Machaeranthera tanacetifolia (Tanseyleaf tansyaster) is a native California herb in the Asteraceae family, recognized by Eastern species at extreme western range limit; highly restricted California distribution.
Tanseyleaf tansyaster is a California native annual found in the eastern desert mountains, including the New York Mountains, in desert scrub and pinyon/juniper woodland at elevations around 1,700 meters. Flowering from May to July, this plant produces striking blue-purple ray flowers 1 to 2 centimeters long with distinctive disk flowers 5 to 7 millimeters in size. Growing bushy and somewhat branched, it reaches heights of 10 to 100 centimeters with puberulent and glandular stems that spread from the base. Its leaves are intricately dissected, typically 3 to 12 centimeters long and divided into 1 to 2 pinnate sections. The fruit is a silky, narrowly obovate structure 3 to 4 millimeters long, topped with a 4 to 6 millimeter pappus.
Identification and appearance
Key characters: Eastern species at extreme western range limit; highly restricted California distribution
Habitat and range
Habitat: Uncommon. Desert scrub, pinyon/juniper woodland
Elevation: +- 1700 m.
Outside California: to Montana, South Dakota, Texas, Mexico
Bloom period
Machaeranthera tanacetifolia blooms May-Jul.
How to tell it apart
vs Symphyotrichum: Machaeranthera has fern-like dissected leaves; Symphyotrichum has simple entire or toothed leaves.; vs Dieteria: Machaeranthera leaves finely dissected like tansy; Dieteria leaves simple, entire to toothed.; vs Felicia: Machaeranthera has deeply divided feathery leaves; Felicia has simple narrow leaves.; vs Erigeron: Machaeranthera has 1-2 times pinnately dissected leaves; Erigeron has simple leaves.; vs Chaetopappa: Machaeranthera has fern-like divided leaves; Chaetopappa has simple leaves.
Frequently asked questions
Is Machaeranthera tanacetifolia native to California?
Yes. Machaeranthera tanacetifolia is native to California (recorded as native).
When does Machaeranthera tanacetifolia bloom?
Machaeranthera tanacetifolia blooms May-Jul.
What plant family does Machaeranthera tanacetifolia belong to?
Machaeranthera tanacetifolia is in the Asteraceae family, genus Machaeranthera.
What habitat does Machaeranthera tanacetifolia grow in?
Machaeranthera tanacetifolia grows in Uncommon. Desert scrub, pinyon/juniper woodland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.